Abstract Catheter-related blood-stream infections (CRBSI) can result in substantial morbidity, undue mortality, prolonged hospital stays, and increased healthcare costs. Based on the national infection control guidelines, an accurate determination of the number of organisms colonizing a catheter is crucial in assessing significant catheter colonization, one of the criteria for the positive determination of CRBSI. Healthcare providers make therapeutic decisions based on the diagnosis of CRBSI, including antibiotic therapy. Therefore, it is extremely important to correctly enumerate the number of organisms colonizing a catheter. Proper and timely diagnosis of catheter- related infections can help healthcare providers make the appropriate management decisions that can prevent complications including sepsis and death. The major goals of this project include the optimization and enhancement of a sensitive and novel technique for detecting microorganisms on intravascular catheters and to assess the comparative efficacy of this method for diagnosis of catheter-related blood-stream infections.